To encourage youth from diverse backgrounds to participate in science, technology, engineering, and math (STEM) fields, it is important to take an ecological approach. Outside of school, parents' values and knowledge have a strong influence in the development of their children's learning in STEM related fields. Based in Digital Youth Divas (DYD), an out-of-school time (OST) STEM program for underserved middle grade girls in Evanston, IL, this exploratory study examined parents' decision-making process when selecting OST STEM programs for their children. We facilitated a parent workshop and conducted interviews with five parents of DYD participants and two staff members. Participants in the study expressed preferences for programs that are free, situated in locations that are easily accessible, and run by highly regarded educational institutions. Parents also identified barriers to participation such as the lack of a parent network, conflicting schedules with other OST activities, and difficulties in understanding the term “STEM”. These results suggest several recommendations for programs to address these barriers, such as designing intriguing program flyers, fostering a parent network, and providing accessible program locations. For researchers and designers of OST STEM programs, this study highlights the importance of taking a family and community-based approach to understanding parent perceptions and challenges.